Case Report: Recurrent pathogenic mutation c.110G>A in DHDDS gene

Recent studies have demonstrated the close association of mutations in the dehydrodolichyl diphosphate synthase (DHDDS) gene with neurodevelopmental disorders and the onset of epilepsy. This report describes a female patient harboring a de novo heterozygous variant c.110G>A (p.Arg37His) in the DHDDS gene, characterized by childhood-onset myoclonus-like movement disorder (at age 6) and late-onset epilepsy (at age 17). The movement disorder was remarkably improved through the levetiracetam+ clonazepam+ haloperidol triple therapy, and epileptic seizures were also effectively controlled. A retrospective analysis of 59 epilepsy patients with DHDDS gene variants revealed significant clinical heterogeneity in disease phenotypes caused by DHDDS mutations. Epilepsy was identified as the predominant symptom, commonly accompanied by movement disorders and varying degrees of intellectual disability. Furthermore, while pathogenic mutations in DHDDS tend to be relatively clustered, no definitive genotype-phenotype correlation has been established. This study highlights the clinical manifestations, imaging features, treatment experiences, and genetic testing results through case reports and literature review, thereby providing crucial references for the clinical diagnosis, treatment, and further research of such diseases.